Bark spectral signatures of one-year-old twigs of different shrubs mainly depend on their biochemical traits


  • Mateja Grašič
  • Bojana Ropert
  • David Gradinjan
  • Alenka Gaberščik



bark, pigments, reflectance, UV-B–absorbing substances, woody plants


The interaction of bark with light depends on the optical properties of the bark, which are important for plant energy balance especially out of the vegetation season. Light reflected from bark also represents a kind of “bark spectral signature” that may be species-specific. This study examines some morphological, biochemical, and physiological traits that may affect the reflectance of the bark of 1-year-old twigs of different shrubs: Corylus avellana, Rosa canina, Ligustrum vulgare, Sambucus nigra, Cornus sericea var. flaviramea, and Viburnum lantana. High variability was seen across these species for morphological, biochemical, and physiological traits, except for photochemical efficiency of photosystem II. The bark spectral signatures differed significantly across these species. The reflectance peak for C. sericea var. flaviramea was in red, for C. avellana in green, and the other species showed a wide peak from green to red light. Redundancy analysis revealed that UV-B–absorbing substances and anthocyanin content, along with outer and inner bark thickness, together explained 61% of the reflectance spectra variability. Outer bark thickness was important for reflectance in UV, violet, and blue, while anthocyanins were important for reflectance in green and yellow. Chlorophyll b was negatively related to the reflectance of visible light. This study revealed great importance of biochemical traits for explaining bark reflectance. Differences in “bark spectral signatures” enable differentiation across species out of the vegetation season.


Aschan, G., Wittmann, C., Pfanz, H., 2001. Age-dependent bark photosynthesis of aspen twigs. Trees, 15 (7), 431-437. DOI:

Atkilt Girma, A., Skidmore, A.K., de Bie, C.A.J.M., Bongers, F., Schlerf, M., 2013. Photosynthetic bark: use of chlorophyll absorption continuum index to estimate Boswellia papyrifera bark chlorophyll content. International Journal of Applied Earth Observation and Geoinformation, 23, 71-80. DOI:

Björkman, O., Demmig, B., 1987. Photon yield of O2 evolution and chlorophyll fluorescence characteristics at 77 K among vascular plants of diverse origins. Planta, 170 (4), 489-504. DOI:

Black, H.L., Harper, K.T., 1979. The adaptive value of buttresses to tropical trees: additional hypotheses. Biotropica, 11 (3), 240. DOI:

Bornman, J., Barnes, P.W., Robinson, S.A., Ballaré, C.L., Flint, S.D., Caldwell, M.M., 2015. Solar ultraviolet radiation and ozone depletion-driven climate change: effects on terrestrial ecosystems. Photochemical and Photobiological Sciences, 14 (1), 88-107. DOI:

Brestic, M., Zivcak, M., 2013. PSII fluorescence techniques for measurement of drought and high temperature stress signal in plants: protocols and applications. In: Rout, G. R., Das, A. B. (eds.): Molecular Stress Physiology of Plants. Springer, Dordrecht, pp. 87-131. DOI:

Caldwell, M.M., 1968. Solar ultraviolet radiation as an ecological factor for alpine plants. Ecological Monographs, 38 (3), 243-268. DOI:

Campbell, S.A., Borden, J.H., 2005. Bark reflectance spectra of conifers and angiosperms: implications for host discrimination by coniferophagous bark and timber beetles. The Canadian Entomologist, 137 (6), 719-722. DOI:

Carrillo-Parra, A., Rosales, M., Wehenkel, C., Foroughbakhch, R., González, H., Garza, F., 2012. Phenols and flavonoids concentration and fungistatic activity of wood and bark of five common tropical species. Tropical and Subtropical Agroecosystems, 15 (3), 621-628.

Damesin, C., 2003. Respiration and photosynthesis characteristics of current-year stems of Fagus sylvatica: from the seasonal pattern to an annual balance. New Phytologist, 158 (3), 465-475. DOI:

Drumm, H., Mohr, H., 1978. The mode of interaction between blue (UV) light photoreceptor and phytochrome in anthocyanin formation of the Sorghum seedling. Photochemistry and Photobiology, 27 (2), 241-248. DOI:

Eyles, A., Pinkard, E.A., O’Grady, A.P., Worledge, D., Warren, C.R., 2009. Role of corticular photosynthesis following defoliation in Eucalyptus globulus. Plant, Cell & Environment, 32 (8), 1004-1014. DOI:

Ferrenberg, S., Mitton, J.B., 2014. Smooth bark surfaces can defend trees against insect attack: resurrecting a ‘slippery’ hypothesis. Functional Ecology, 28 (4), 837-845. DOI:

Filippou, M., Fasseas, C., Karabourniotis, G., 2007. Photosynthetic characteristics of olive tree (Olea europaea) bark. Tree Physiology, 27 (7), 977-984. DOI:

Gould, K.S., Markham, K.R., Smith, R.H., Goris, J.J., 2000. Functional role of anthocyanins in the leaves of Quintinia serrata A. Cunn. Journal of Experimental Botany, 51 (347), 1107-1115. DOI:

Grašič, M., Dobravc, M., Golob, A., Vogel-Mikuš, K., Gaberščik, A., 2019a. Water shortage reduces silicon uptake in barley leaves. Agricultural Water Management, 217, 47-56. DOI:

Grašič, M., Malovrh, U., Golob, A., Vogel-Mikuš, K., Gaberščik, A., 2019b. Effects of water availability and UV radiation on silicon accumulation in the C4 crop proso millet. Photochemical & DOI:

Photobiological Sciences, 18, 375-386.

Grašič, M., Škoda, B., Golob, A., Vogel-Mikuš, K., Gaberščik, A., 2019c. Barley and spelt differ in leaf silicon content and other leaf traits. Biologia, 74, 929-939. DOI:

Henrion, W., Tributsch, H., 2009. Optical solar energy adaptations and radiative temperature control of green leaves and tree barks. Solar Energy Materials and Solar Cells, 93 (1), 98-107. DOI:

Ivanov, A.G., Krol, M., Sveshnikov, D., Malmberg, G., Gardeström, P., Hurry, V., Oquist, G., Huner, N.P., 2006. Characterization of the photosynthetic apparatus in cortical bark chlorenchyma of Scots pine. Planta, 223 (6), 1165-1177. DOI:

Johnstone, D., Tausz, M., Moore, G., Nicolas, M., 2014. Bark and leaf chlorophyll fluorescence are linked to wood structural changes in Eucalyptus saligna. AoB PLANTS, 6, plt057. DOI:

Klančnik, K., Gradinjan, D., Gaberščik, A., 2015. Epiphyton alters the quantity and quality of radiation captured by leaves in submerged macrophytes. Aquatic Botany, 120, Part B, 229-235. DOI:

Kocurek, M., Pilarski, J., 2012. Implication of stem structures for photosynthetic functions in select herbaceous plants. Polish Journal of Environmental Studies, 21 (6), 1687-1696.

Kokaly, R.F., Skidmore, A.K., 2015. Plant phenolics and absorption features in vegetation reflectance spectra near 1.66 μm. International Journal of Applied Earth Observation and Geoinformation, 43, 55-83. DOI:

Kumar Das, P., Geul, B., Choi, S.-B., Yoo, S.-D., Park, Y.-I., 2011. Photosynthesis-dependent anthocyanin pigmentation in Arabidopsis. Plant Signaling & Behavior, 6 (1), 23-25. DOI:

Larcher, W., 2003. Physiological Plant Ecology: Ecophysiology and Stress Physiology of Functional Groups, 4th ed. Springer-Verlag, Berlin, 514 pp.

Lepš, J., Šmilauer, P., 2003. Multivariate analysis of ecological data using CANOCO. Cambridge University Press, Cambridge, 269 pp. DOI:

Levizou, E., Manetas, Y., 2007. Photosynthetic pigment contents in twigs of 24 woody species assessed by in-vivo reflectance spectroscopy indicate low chlorophyll levels but high carotenoid/ chlorophyll ratios. Environmental and Experimental Botany, 59 (3), 293-298. DOI:

Lev-Yadun, S., Gould, K.S., 2008. Role of anthocyanins in plant defence. In: Winefield, C., Davies, K., Gould, K. (eds.): Anthocyanins. Springer, New York, pp. 22-28. DOI:

Lichtenthaler, H.K., Buschmann, C., 2001a. Extraction of photosynthetic tissues: chlorophylls and carotenoids. Current Protocols in Food Analytical Chemistry, 1, 165-170.

Lichtenthaler, H.K., Buschmann, C., 2001b. Chlorophylls and carotenoids: measurement and characterization by UV-VIS spectroscopy. Current Protocols in Food Analytical Chemistry, 1, 171-178.

Mancuso, S., Marras, A.M., 2003. Different pathways of the oxygen supply in the sapwood of young Olea europaea trees. Planta, 216 (6), 1028-1033. DOI:

Manetas, Y., Yiotis, C.Y., 2009. Evidence for light-independent and steeply decreasing PSII efficiency along twig depth in four tree species. Photosynthetica, 47 (2), 223-231. DOI:

Nilsen, E.T., 1995. Stem Photosynthesis: Extent, Patterns, and Role in Plant Carbon Economy. In: Gartner, B.L. (ed.): Plant Stems: Physiology and Functional Morphology. Academic Press, New York, pp. 223-240. DOI:

Pfanz, H., 1999. Photosynthetic performance of twigs and stems of trees with and without stress. Phyton, 39 (3), 29-33.

Pfanz, H., Aschan, G., Langenfeld-Heyser, R., Wittmann, C., Loose, M., 2002. Ecology and ecophysiology of tree stems: corticular and wood photosynthesis. Naturwissenschaften, 89 (4), 147-162. DOI:

Pilarski, J., 1999. Gradient of photosynthetic pigments in the bark and leaves of lilac (Syringa vuigaris L.). Acta Physiologiae Plantarum, 21 (4), 365-373. DOI:

Pilarski, J., Tokarz, K., Kocurek, M., 2008. Optical properties of the cork of stems and trunks of beech (Fagus sylvatica L.). Polish Journal of Environmental Studies, 17 (5), 773-779.

Poorter, L., McNeil, A., Hurtado, V.-H., Prins, H.H.T., Putz, F.E., 2014. Bark traits and life‐history strategies of tropical dry and moist forest trees. Functional Ecology, 28 (1), 232-242. DOI:

Romero, C., 2014. Bark Structure and Functional Ecology. In: Cunningham, A.B., Campbell, B.M., Luckert, M.K. (eds.): Bark: use, management, and commerce in Africa. Advances in Economic Botany. Vol. 17. New York Botanical Garden Press, New York, pp. 5-25.

Romero, C., Bolker, B.M., Edwards, C.E., 2009. Stem responses to damage: the evolutionary ecology of Quercus species in contrasting fire regimes. New Phytologist, 182 (1), 261-271. DOI:

Samanta, A., Das, G., Das, S., 2011. Roles of flavonoids in plants. International Journal of Pharmaceutical Science and Technology, 6 (1), 12-35.

Schreiber, U., Kühl, M., Klimant, I., Reising, H., 1996. Measurement of chlorophyll fluorescence within leaves using a modified PAM fluorometer with a fiber-optic microprobe. Photosynthesis Research, 47 (1), 103-109. DOI:

Sibley, J.L., Ruter, J., Eakes, D.J., 1999. Bark anthocyanin levels differ with location in cultivars of red maple. HortScience, 34 (1), 137-139. DOI:

Smith, J.L., Burritt, D.J., Bannister, P., 2000. Shoot dry weight, chlorophyll and UV-B-absorbing compounds as indicators of a plant’s sensitivity to UV-B radiation. Annals of Botany, 86 (6), 1057-1063. DOI:

Solhaug, K., Haugen, J., 1998. Seasonal variation of photoinhibition of photosynthesis in bark from Populus tremula L. Photosynthetica, 35 (3), 411-417. DOI:

ter Braak, C.J.F., Šmilauer, P., 2002. CANOCO Reference Manual and CanoDraw for Windows User’s Guide: Software for Canonical Community Ordination (Version 4.5). Microcomputer Power, Ithaca, 500 pp.

Tewari, L.M., Tewari, G., Nailwal, T., Pangtey, Y.P.S., 2009. Bark factors affecting the distribution of epiphytic ferns communities. Nature and Science, 7 (5), 76-81.

Tokarz, K., Pilarski, J., 2005. Optical properties and the content of photosynthetic pigments in the stems and leaves of the apple-tree. Acta Physiologiae Plantarum, 27 (2), 183-191. DOI:

Wittmann, C., Aschan, G., Pfanz, H., 2001. Leaf and twig photosynthesis of young beech (Fagus sylvatica) and aspen (Populus tremula) trees grown under different light regime. Basic and Applied Ecology, 2 (2), 145-154. DOI:

Wittmann, C., Pfanz, H., 2007. Temperature dependency of bark photosynthesis in beech (Fagus sylvatica L.) and birch (Betula pendula Roth.) trees. Journal of Experimental Botany, 58 (15-16), 4293-4306. DOI:

Wittmann, C., Pfanz, H., 2008. General trait relationships in stems: a study on the performance and interrelationships of several functional and structural parameters involved in corticular photosynthesis. Physiologia Plantarum, 134 (4), 636-648. DOI:

Wittmann, C., Pfanz, H., 2014. Bark and woody tissue photosynthesis a means to avoid hypoxia or anoxia in developing stem tissues. Functional Plant Biology, 41 (9), 940-953. DOI:

Wittmann, C., Pfanz, H., 2016. The optical, absorptive and chlorophyll fluorescence properties of young stems of five woody species. Environmental and Experimental Botany, 121, 83-93. DOI:






Original Research Paper

How to Cite

Grašič, M., Ropert, B., Gradinjan, D., & Gaberščik, A. (2021). Bark spectral signatures of one-year-old twigs of different shrubs mainly depend on their biochemical traits. Acta Biologica Slovenica, 64(1), 56-69.

Similar Articles

1-10 of 73

You may also start an advanced similarity search for this article.

Most read articles by the same author(s)

1 2 > >>